The present embodiments relate to medical diagnostic imaging. In particular, volume imaging of velocity is provided.
Color Doppler velocity data contains information about both the magnitude and direction of flow. During volume rendering color Doppler velocity data, samples of color Doppler velocity data are interpolated and composited together along viewing rays. Compositing velocity data with different signs may cause the flow direction of the composited result to be ambiguous or unexpected. For example, if the compositing operates on post-color-mapped (RGBA) samples, hues representative of positive and negative flows (e.g., reddish and bluish hues) mix to produce magenta-hued colors. The direction of magenta is ambiguous as the user expects reddish or bluish for towards and away from the transducer. If the compositing operates on pre-color-mapped velocity data, compositing positive and negative data may lead to no flow at all as the compositing causes the flow velocities along the ray to cancel each other out.